Holding is just one factor. It still requires PPS to rise because that is where the presure comes fromm. That means more buys than sells.
But there is always someone selling. First, not everyone is playing the same game. Daytraders will buy into rise but sell that rise. You hear "long squeeze" ... it's not really a squeeze but panic selling. People see the price drop and sell just like people see price rise and buy. It's never as simple as it sounds